'Well, you are about to start the greatest improvisation of all. With no script. No idea what's going to happen, often with people and places you have never seen before. And you are not in control. So say "yes." And if you're lucky, you'll find people who will say "yes" back.'

'Some groups (Second City, most notably) will use improv as a basis for their sketch. They will present a show of improv for the purpose of gleaning material which can be worked up into viable sketches. It should be noted that this is not "sketch-based improv," but "improv-derived sketch." While the improv is used as a launching point for the sketch, it does not make the sketch improv.'